Iran′s Veterinary Organisation confirmed Saturday that a batch of 135 dead swans found in the northern province of Gilan have tested positive for the highly pathogenic H5N1 strain of bird flu, AFP reported.

The cases are the first time the virus has been detected in the Islamic republic.

"Highly pathogenic avian influenza has been detected in 135 wild swans in two places in the Anzali wetlands in northern Iran," Iranian veterinary chief Hossein Hassani told AFP.

"There are no cases in any other parts of the country. Nothing has been detected in the free-range or factory-bred birds. There is no concern about human contraction," he asserted.

Iran′s veterinary service had on Tuesday said that pending further tests, the wild swans had only been confirmed as having the broad H5 virus category which only kills birds.